This invention relates to the addition of alkyl groups to non-halogen containing silanes to produce more highly alkylated silanes. More particularly, this invention relates to a process for reacting silanes with alkyl halides in the presence of a halide-accepting metal with or without the presence of a catalyst. The process, as described, can convert silanes to more valuable intermediates and to organosilanes which are easier to handle.
As an early example of the preparation of organosilicon compounds using metallic reagents, Kippling and Dilthey both demonstrated the alkylation of tetrachlorosilane by reaction with an organomagnesium halide, the well-known Grignard process.
Hurd, J. Am. Chem. Soc. (1945), Vol. 67, pp. 1545-1548, and Hurd, U.S. Pat. No. 2,403,370, issued July 2, 1946, disclose the alkylation of tetrachlorosilane and various methylchlorosilanes by passing the vapors of these chlorosilanes together with an alkyl halide over finely divided aluminum, zinc, or other reactive metal at elevated temperatures, 300.degree.-500.degree. C. Hurd discloses that a reaction occurs under these conditions in which chlorine groups on the chlorosilane are replaced by alkyl groups.
Straussberger et al., U.S. Pat. No. 4,155,927, issued May 22, 1979, discloses a process for preparing trimethylchlorosilane which comprises reacting methyldichlorosilane with methyl chloride and metallic aluminum in the presence of a diatomite.
Chadwick et al., pending U.S. application No. 07/432,005, filed Nov. 6, 1989 discloses a process for reacting a halide of silicon with an alkyl halide in the presence of a halogen accepting metal such as aluminum or zinc and a catalyst.
Chadwick et al., pending U.S. application No. 07/439,073, filed Nov. 17, 1989, discloses a process for reacting a halogen-containing disilane with an alkyl halide in the presence of a halogen accepting metal such as aluminum or zinc and a catalyst.
The above cited references do not teach a process for alkylating a non-halogen containing silane by reaction with an alkyl halide and a halogen accepting metal with or without the presence of a catalyst.